Resource Management for a Mobile Telephone Terminal

ABSTRACT

A resource management unit for a mobile telephone terminal, with the terminal comprising radio transmission/reception means for transmitting and receiving radio frequency signals corresponding to bursts of symbols during allocated time slots, and a device able to operate in a first mode and in a second mode, said device interfering less with the transmission/reception of radio frequency signals when it is in the first mode than when it is in the second mode. The resource management unit is able to cause the device to change from one of the first and second modes to the other of the first and second modes during the same time slot.

TECHNICAL FIELD

This invention relates to the field of mobile telephony, particularlythe field of Time Division Multiple Access (TDMA) telephony.

TECHNOLOGICAL BACKGROUND

A mobile telephone terminal conventionally comprises a means fortransmitting or receiving radio frequency signals in packets known asbursts.

The terminal also comprises various devices, for example an input/outputmanagement device, a power supply, a DC-DC regulator, a baseband signalprocessor, a means of managing the user interface, or other deviceswhich could interfere with the transmission/reception of radio frequencysignals.

During operation, these devices can degrade the quality of the radiofrequency signals emitted by the radio transmitter/receiver or the datareceived from them.

One possible approach to avoiding such degradation in quality consistsof protecting the radio transmitter/receiver from these interferingdevices, by shielding or by having the interfering devices sufficientlydistanced from the radio transmitter/receiver.

Another possible approach, known as TDI (Time Domain Isolation),consists of not making use of the radio transmitter/receiver at the sametime as the interfering devices, which can then be placed in proximityto each other. This approach enables a higher level of integration. Inthis approach, the clock of the baseband signal processor is slowed ordisabled prior to sending or receiving bursts of radio frequencysignals, and the clock is reinstated once the bursts are sent orreceived.

However, this approach results in reducing the activity of theinterfering devices, adversely impacting the features and servicesprovided by such devices. The reduction in activity can be more or lessconsiderable depending on the standard. For example, with the GPRSstandard (General Burst Radio Services), the baseband signal processorwould be stopped for about 70% of the time.

SUMMARY OF THE INVENTION

A need therefore exists for decreasing the reduction in the activity ofthe interfering devices, while integrating radio communication qualityand resources.

The invention proposes a resource management unit for a mobile telephoneterminal, said terminal comprising radio transmission/reception meansfor transmitting/receiving bursts of radio frequency signals, asynchronization means for providing allocated time slots, with each timeslot allocated for transmitting/receiving radio frequency signalscorresponding to a burst, and at least one device able to operate in afirst mode and in a second mode, this device or devices interfering lesswith the transmitting/receiving of radio frequency signals when it(they)is(are) in the first mode than when it(they) is(are) in the second mode.The resource management unit is able to cause this(these) device(s) tochange from one of the first or second modes to the other of the firstor second modes during the same time slot.

Also proposed is a resource management method for a mobile telephoneterminal. In this method, during an allocated time slot, the device(s)is(are) caused to change from one of the first or second modes to theother of the first or second modes during the same time slot.

Thus, the device is in the first mode (less interfering) during only apart of the period corresponding to the transmission/reception of aburst, which improves the performance of the device.

The resource management unit can comprise various means for changingfrom the first mode to the second mode. For example, the unit cancomprise means for cutting off a clock, for changing the value of anoperating mode bit of the device, for decreasing or increasing the clockfrequency of the device, introducing latency time, a means forsuppressing or modifying a power source for the device, a means fordecreasing or increasing voltage to the device, a spread spectrum means,a means for limiting the spectral content of the device, or other means.

The invention is therefore in no way limited by the form of the meansfor changing to the first mode.

There can be one or more devices able to operate in two different modes,for example an input/output management device, a power supply, a DC-DCregulator, a baseband signal processing means, a user interfacemanagement means, or other devices.

The device, when it is in the second mode (normal operation), interfereswith the transmission/reception of radio frequency signals.“Interference with the transmission/reception of radio frequencysignals” is understood to mean both the interference affecting the radiofrequency transmission/reception and the interference affecting theradio frequency signals transmitted/to be received.

The choice of the moment(s) when the change is made from one mode toanother can be made when the management unit is manufactured. This unit,for example a circuit or a chip, can then be arranged to cause a devicesuch as a CPU (Central Processing Unit) to enter the first mode, forexample an inactive or standby mode, during a given period within a timeslot.

This choice of the moment(s) for changing from one mode to another canbe made during assembly with the other components of a mobile telephoneterminal in a circuit capable for example of deactivating or slowingcertain digital processing means during a period whose duration,beginning and/or end is(are) programmable. The choice can thus be madeas a function of the environment of the circuit when it is assembled.

The choice of the moment(s) for changing from one mode to another can bemade during the service life of the mobile telephone terminal.

The invention is therefore not limited by the circumstances at the timeof the choice of moment(s) for changing from one mode to another. Thischoice can be made by technical means or by a person.

Advantageously, this choice of the moment(s) for changing from one modeto the other is made in order to satisfy a transmission and/or receptionquality criterion, for example in order to satisfy the requirements of astandard such as the 3GPP standard (3rd Generation Partnership Project).

By imposing such a constraint, one can choose the moment(s) for changingfrom one mode to another, for example so that the consequences ofinterference caused by the operation of a digital processing meansduring the transmission/reception of radio frequency signals remainlimited.

The moment(s) for changing from one mode to another can be chosen as afunction of an estimation of the interference generated in thetransmitted or received symbols when operating in the first and/orsecond mode of the device during the transmission/reception of radiofrequency signals corresponding to these transmitted or receivedsymbols. The moment(s) for changing modes are thus chosen as a functionof an estimated degradation, to avoid the device operating normally (inthe second mode) when such operation could affect the quality of thetransmission/reception.

The degradation can be estimated by technical means, for example a radiocommunication tester, a microcontroller, or a circuit for estimating thequality of the signals sent or received, or by a person.

Advantageously, the device can comprise a means for receiving at leastone measured quality parameter value, with the choice of the moment(s)for changing from one mode to the other being a function of this atleast one received value. The use of measured data thus allows choosingthe periods of normal operation (second mode) and the periods ofoperating with less interference (first mode), on the basis of objectivedata.

A measurement step can be carried out, or previous measurements can beused.

For example, one can measure an error rate, such as the BER (Bit ErrorRate) measured over a certain number of received bursts, asignal-to-noise ratio or SNR, a phase error measurement such as EVM(Error Vector Magnitude), a strength measurement, and/or an analysis ofthe spectral content of transmitted or received signals.

The moments for changing from one mode to another can be chosen suchthat the measured parameters satisfy the requirements of a standard, forexample the 3GPP standard.

The measurements can be made during the service life of the terminal.Symbol, block, burst, or other errors can in fact be counted due to aredundancy in or prior knowledge of part of the signal received. Forexample, a cyclic redundancy check or CRC can be implemented. Theduration, start and/or end of the normal periods of operation and theless interfering periods of operation can thus be adapted according tothe results of such an error count.

The invention is therefore in no way limited by the circumstances of themeasurement, or by the manner in which this measurement is done.

Advantageously, since each time slot is divided into predeterminedintervals of time, the moment of changing from one of the first andsecond modes to the other of the first and second modes can be chosensuch that the device operates in the second mode for a period of timecomprising one or more of these intervals of time. Each interval of timecorresponds in fact to a specific function, for example sending payloaddata, estimating a channel state, or waiting for the next burst. Theperiod of time of normal operation is therefore chosen such that thedevice continues to operate normally when a function judged to benon-essential is carried out.

Advantageously, the period of time of normal operation can comprise aninterval of time in the time slot intended for thetransmission/reception of guard symbols at the beginning and/or end ofthe burst of symbols corresponding to the time slot.

In fact, as these guard symbols are provided primarily to avoid spectralbroadening, they do not carry useful information, so any degradationcaused by the normal operation of the device has relatively littleeffect on the quality of the transmission/reception. By allowing thedevice to operate normally during the transmission/reception of guardsymbols, the active time of the device can be increased while thequality remains constant.

Advantageously, the period of normal operation can comprise an intervalof time in the slot allocated for the transmission/reception of tailsymbols. The function of these symbols is to mark the start or end oftrellis coding, and do not actually correspond to useful information.

Advantageously, the period of normal operation can comprise a portion ofan interval of time in the time slot allocated for thetransmission/reception of useful symbols. In fact, the coding of thechannel can be sufficiently robust that any degradation caused by theoperation of the device has no real effect on the decoded data.

Advantageously, the period of normal operation can comprise at least aportion of an interval of time intended for sending a training sequencefor channel estimation. When the communication takes place under goodconditions, the consequences of any interference in this sequence can berelatively limited.

Alternatively, the period of normal operation can only partially coverone or more intervals of time. A period of normal operation can bechosen that covers only a part of an interval of time, particularly ifthe channel coding is sufficiently robust so that the data correspondingto all the symbols transmitted/received during this interval of time canbe recovered without errors or with an error rate that is below athreshold.

The change from one mode to the other mode can be done during thereception or transmission of a burst. The moment of the change from onemode to the other mode is not necessarily determined solely by theprovided synchronization. One can in fact choose a moment for the changeas a function of the data received or sent, for example the volume ofdata received or sent, the type of data received or set (guard interval,training sequence, payload, etc.), or other.

Also proposed is a computer program product stored in a memory of aterminal, for example a mobile telephone terminal, and/or on a removablemedium able to cooperate with a reader of this terminal, and/ordownloadable via a telecommunications network, wherein it comprisesinstructions for implementing the method described above when it isloaded into the memory of a processor and executed on this processor.

The resource management unit can be separate from the other digitalprocessing means of the terminal, in particular the baseband signalprocessing means. For example, the resource management unit comprises amicrocontroller in communication with a circuit that integrates thebaseband processing means.

The resource management unit, the radio frequency signaltransmission/reception means and/or the device can be integrated intoone circuit. A circuit is therefore proposed that is intended for amobile telephone terminal, comprising a device able to operate in thefirst or the second mode, for example a baseband signal processingmeans, and comprising the resource management unit described above.

Also proposed is a mobile telephone terminal comprising radiotransmission/reception means for transmitting and receiving radiofrequency signals corresponding to symbol bursts during respectiveallocated time slots, a synchronization means, a device able to operatein the first and second mode, and a resource management unit asdescribed above.

Other features and advantages of the invention will be apparent from thefollowing description.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 shows an example of a mobile telephone terminal integrating aprocessor according to an embodiment of the invention.

FIG. 2 shows timing charts illustrating an embodiment of the invention.

FIG. 3 shows a timing chart representing the different intervals of timefor an exemplary time slot.

FIG. 4 is a flow chart of an exemplary process for choosing the momentsfor changing from one mode to the other, according to an embodiment ofthe invention.

The same references may be used in different figures to representidentical or similar objects.

DETAILED DESCRIPTION OF EMBODIMENTS

FIG. 1 shows a mobile telephone terminal 100 with a screen 110. Thisterminal is compliant with the GSM (Global System for MobileCommunications) or GPRS (General Burst Radio Service) standard.

The terminal 100 comprises radio transmission/reception means,consisting for example of an antenna 120 and an analog and/or digitalcircuit 130 connected (directly or indirectly) to the antenna 120. Thesemeans 120, 130 allow transmitting and receiving radio frequency signals.

The terminal 100 uses Time Division Multiple Access, meaning the radiofrequency signals are sent or received in a discontinuous manner, inbursts, as represented in the timing chart 300 in FIG. 2.

In this timing chart 300, two frames are represented. The frame periodcorresponding to one frame is divided into eight frame sub-periods,numbered from 0 to 7 in FIG. 2.

Of these eight frame sub-periods, five comprise a time slot during whichthe terminal is configured in the mode awaiting the receipt of a burstor is configured to send a burst.

Three slots are allocated for receiving a burst (slots labeled R forReceive) and two slots are allocated for transmitting a burst (slotslabeled T for Transmit).

A portion of time, labeled M, is dedicated to monitoring the surroundingradio frequency signals for a given frequency. This portion of time Mdoes not necessarily constitute a time slot, as the corresponding timecan be dedicated to listening for signal strength, not to waiting for aburst.

The beginnings and ends of the frame sub-periods and time slots areknown after synchronization is performed by the synchronization means.This synchronization means can be integrated in a circuit or amicrocontroller, for example the circuit denoted as 140 in FIG. 1.

A buffer 135 is in communication with the circuit 140 and with thecircuit 130, to allow temporarily storing data received or to betransmitted, according to methods well know to those skilled in the art.

The circuit 140 comprises a digital processing part 142 for managing thebaseband signals, this digital processing part as well as most of theother components of the terminal 100 being well known to those skilledin the art of mobile telephony.

Also conventionally, this digital processing part 142 is synchronized bya clock 143.

The timing chart 310 of FIG. 2 corresponds to a resource managementprocess using the TDI approach. This timing chart shows a signal fordeactivating the digital processing part by not supplying the clocksignal (“clock gating”). In this approach, the clock is disconnectedfrom the digital processing part for the entirety of each of the fivetime slots R₀, R₁, R₂, T₄, T₅.

The digital processing part is also deactivated during a small part ofthe frame sub-periods preceding and following the time slots R₀, R₁, R₂,T₄, T₅ (sub-periods 3, 6 and 7), and also during the portion of time M.

The timing chart 320 illustrates an exemplary embodiment of theinvention. This timing chart also shows a signal to deactivate thedigital processing part by not supplying the clock signal. For each ofthe time slots R₀, R₁, R₂, T₄, T₅, the digital processing part is onlydeactivated during a period corresponding to only a part of this timeslot. The digital processing part thus operates normally during the restof the time slot R₀, R₁, R₂, T₄, T₅.

This period during which the digital processing part is deactivated canpossibly be adjusted. In FIG. 2, double arrows represent the parts P₀,P₀′, P₁, P₁′, P₂, P₂′, P₄, P₄′, P₅, P₅′ of the slots during which themoment of changing from the first mode to the second mode, and thereverse, can be chosen.

In addition, the digital processing part is allowed to operate normallyduring the portion of time M. If the quality of the transmission issufficient, it is possible to do without analyzing the results from thismonitoring or to tolerate the error related to the interferencegenerated by the digital processing part. To return to FIG. 1, theprocessor 140 comprises a resource management unit 141 comprisingdeactivation means for isolating the clock 143 from the digitalprocessing part 142, for example by modifying the value of a mode bitnot represented. In this manner, the device 141 manages thenon-supplying of a clock signal to the part 142.

The deactivation or slowing can be done by other means, for example bymodifying the value of a mode bit in order to change to inactive mode,particularly if the part 142 is asynchronous.

For each time slot, the device 141 is programmed to deactivate this part142 during only a part of the time slot, such that the digitalprocessing part operates normally during the rest of the slot. Thedevice 141 can have been programmed with a computer program comprisinginstructions for modifying a value of a mode bit at a given momentinside a time slot. The beginning and end moments of the time slot areknown after synchronization.

FIG. 3 shows a timing chart representing the different intervals of timefor an exemplary time slot 340. This time slot 340 allows receiving orsending a burst of a duration of 624 Qb, where

${{Qb} = {\frac{12}{13.10^{- 6}}\mspace{14mu} {seconds}}},$

which corresponds to 156 symbols.

The slot 340 comprises two intervals of time 360, 360′ intended for thetransmission or reception of guard symbols, at the beginning and end ofthe burst. Each time interval 360, 360′ corresponds to the transmissionor reception of four guard symbols.

The slot 340 additionally comprises two intervals of time 370, 370′intended for the transmission or reception of respective beginning andend tail symbols.

The slot 340 additionally comprises two intervals of time 380, 380′intended for the transmission or reception of useful symbols. These twointervals of time are separated by an interval of time 350 intended fortransmitting a training sequence for channel estimation.

For example, one can choose to allow the part 142 in FIG. 1 to operatenormally during the intervals of time 360, 360′, since these correspondto the transmission/reception of guard symbols. When there are severalslots in succession, the interval 360′ is adjacent to the interval 360of the next slot. As these intervals 360, 360′ correspond to foursymbols, the part 142 can then operate normally during a periodcorresponding to eight symbols.

If one chooses to allow the part 142 to operate normally during theintervals of time 370, 370′ as well, the part 142 can then operatenormally for a period corresponding to fourteen symbols.

FIG. 4 is a flow chart of an exemplary algorithm of a process forchoosing the moments for changing from the first mode to the secondmode, and from the second mode to the first mode.

During the service life of a mobile telephone terminal, a cyclicredundancy check is performed during a step 400. This step is conductedusing redundancy bits introduced in the channel coding, according to aprocess well known to those skilled in the art.

A block error rate BLER is then calculated in a step 401, as a functionof the results of the cyclic redundancy check. This provides ameasurement of a transmission or reception quality parameter.

Alternatively, a SNR can be measured using a known sequence of symbols.

This value is compared to a threshold during a step 403: if the BLER istoo high, then for each slot R_(i) or T_(i), the duration of a time slotadjustment part P_(i) is increased during a step 402, such that theperiod with the least interference sees its length increase. The digitalprocessing part is thus deactivated longer, in a manner that globallydecreases the interference on the symbols transmitted or received.

For each time slot, one or more period(s) of normal operation is(are)defined in a manner that fills the time in the slot not filled by thefirst period(s) of less interference.

These steps 400, 401, 403, 402 can be repeated at regular intervals. Thealgorithm includes a wait step 404 for this purpose, between twomeasurement steps 400.

1-11. (canceled)
 12. A resource management unit for a mobile telephoneterminal, wherein the terminal includes a radio circuit and an antennafor transmitting and receiving bursts of radio frequency signals duringtime slots that have been respectively allocated for such transmissionand reception and whose timing has been identified by a synchronizationcircuit of the terminal, wherein the resource management unit isconfigured to change an operating mode of at least one device in theterminal, during a single time slot, between a first mode in which theat least one device interferes less with said transmission and receptionand a second mode in which the at least one device interferes more withsaid transmission and reception.
 13. The resource management unitaccording to claim 12, wherein the resource management unit isconfigured to determine the moment within said time slot for changingthe operating mode of the at least one device as a function of a valueobtained for at least one measured quality parameter.
 14. The resourcemanagement unit according to claim 12, wherein said time slot is dividedinto predefined intervals of time, and wherein the resource managementunit is configured to determine the moment within said time slot forchanging the operating mode of the at least one device such that said atleast one device operates in the second mode during a period of timecomprising at least one of said intervals of time.
 15. The resourcemanagement unit according to claim 14, wherein the period of time duringwhich said at least one device operates in the second mode comprises aninterval of time that is adjacent to the beginning or end of the timeslot and is intended for the transmission or reception of guard symbols.16. The resource management unit according to claim 14, wherein theperiod of time during which said at least one device operates in thesecond mode comprises at least a portion of an interval of time, withinthe time slot, intended for the transmission or reception of usefulsymbols.
 17. The resource management unit according to claim 12, whereinthe resource management unit is configured to change the operating modeof the at least one device by at least one of: cutting off a clocksignal intended for the at least one device; modifying a clock frequencyof the at least one device; cutting off or modifying a power sourceintended for the at least one device; modifying a voltage to the atleast one device; and limiting the spectral content of the at least onedevice.
 18. The resource management unit according to claim 12, whereinthe mobile telephone terminal uses TDMA (Time Division Multiple Access).19. The resource management unit according to claim 12, wherein theresource management unit is configured to change the operating mode ofthe at least one device during the transmission or reception of a singleburst by the radio circuit and antenna in said time slot.
 20. Theresource management unit according to claim 12, wherein thesynchronization circuit identifies the timing of said time slots byidentifying boundaries between said time slots, and wherein the resourcemanagement unit is configured to time the change between the first andsecond modes to occur independently from the times at which saidboundaries occur.
 21. A circuit for a mobile telephone terminal, whereinthe terminal includes a radio circuit and an antenna for transmittingand receiving bursts of radio frequency signals during time slots thathave been respectively allocated for such transmission and reception andwhose timing has been identified by a synchronization circuit of theterminal, wherein the circuit comprises a resource management unit thatis configured to change an operating mode of at least one device in theterminal, during a single time slot, between a first mode in which theat least one device interferes less with said transmission and receptionand a second mode in which the at least one device interferes more withsaid transmission and reception.
 22. The circuit of claim 20, whereinthe circuit further comprises a baseband signal processor and whereinsaid at least one device includes said baseband signal processor.
 23. Amethod for managing resources of a mobile telephone terminal thatincludes a radio circuit and an antenna for transmitting and receivingbursts of radio frequency signals during time slots that have beenrespectively allocated for such transmission and reception and whosetiming has been identified by a synchronization circuit of the terminal,wherein the method comprises changing an operating mode of at least onedevice in the terminal, during a single time slot, between a first modein which the at least one device interferes less with said transmissionand reception and a second mode in which the at least one deviceinterferes more with said transmission and reception.
 24. The method ofclaim 23, further comprising determining the moment within said timeslot for changing the operating mode of the at least one device as afunction of a value obtained for at least one measured qualityparameter.
 25. The method of claim 23, wherein said time slot is dividedinto predefined intervals of time, and wherein the method furthercomprises determining the moment within said time slot for changing theoperating mode of the at least one device such that said at least onedevice operates in the second mode during a period of time comprising atleast one of said intervals of time.
 26. The method of claim 25, whereinthe period of time during which said at least one device operates in thesecond mode comprises an interval of time that is adjacent to thebeginning or end of the time slot and is intended for the transmissionor reception of guard symbols.
 27. The method of claim 25, wherein theperiod of time during which said at least one device operates in thesecond mode comprises at least a portion of an interval of time, withinthe time slot, intended for the transmission or reception of usefulsymbols.
 28. The method of claim 23, wherein said changing compriseschanging the operating mode of the at least one device by at least oneof: cutting off a clock signal intended for the at least one device;modifying a clock frequency of the at least one device; cutting off ormodifying a power source intended for the at least one device; modifyinga voltage to the at least one device; and limiting the spectral contentof the at least one device.
 29. The method of claim 23, wherein saidchanging comprises changing the operating mode of the at least onedevice during the transmission or reception of a single burst by theradio circuit and antenna in said time slot.
 30. The method of claim 23,further comprising timing the change between the first and second modesto occur independently from the times at which boundaries between saidtime slots occur.
 31. A computer program product stored on a computerreadable medium and comprising computer program instructions that, whenexecuted by a processor of a mobile telephone terminal that includes aradio circuit and an antenna for transmitting and receiving bursts ofradio frequency signals during time slots that have been respectivelyallocated for such transmission and reception and whose timing has beenidentified by a synchronization circuit of the terminal, cause theterminal to change an operating mode of at least one device in theterminal, during a single time slot, between a first mode in which theat least one device interferes less with said transmission and receptionand a second mode in which the at least one device interferes more withsaid transmission and reception.